Shellfish exploitation during the Oakhurst at AUTHORS: Klipdrift Cave, southern Cape, South Africa Kokeli P. Ryano1,4 Karen L. van Niekerk2 Sarah Wurz2,3 Christopher S. Henshilwood2,4 Klipdrift Cave in the southern Cape, South Africa, provides new insights into shellfish harvesting during the Later Stone Age (14–9 ka) period associated with the Oakhurst techno-complex. Two shellfish species AFFILIATIONS: dominate: Turbo sarmaticus and Dinoplax gigas. An abrupt shift in the relative frequencies of these species 1Department of History, School of Humanities, University of Dodoma, occurs in the middle of the sequence with T. sarmaticus almost completely replacing D. gigas. The shift in Dodoma, Tanzania dominant species is likely due to environmental change caused by fluctuating sea levels rather than change 2SFF Centre for Early Sapiens Behaviour (SapienCE), Department of in sea surface temperatures. The shellfish assemblage shows that local coastal habitats at Klipdrift Cave Archaeology, History, Cultural Studies were somewhat different from those of contemporaneous sites in the southern Cape. Although the shellfish and Religion, University of Bergen, Bergen, Norway specimens are smaller at Klipdrift Cave than those from Middle Stone Age localities such as Blombos Cave, 3School of Geography, Archaeology there is no robust indication that larger human populations at Klipdrift Cave during the Oakhurst period might and Environmental Studies, University have caused this change in size. Environmental or ecological factors could have restricted shellfish growth of the Witwatersrand, Johannesburg, South Africa rates as some experimental works have suggested, but this possibility also remains to be further explored. 4Evolutionary Studies Institute, University of the Witwatersrand, Significance: Johannesburg, South Africa • The dominance of D. gigas and T. sarmaticus at Klipdrift Cave is surprising, as it indicates a local habitat slightly different from other similar sites during the Oakhurst period. CORRESPONDENCE TO: Kokeli Ryano • The shift in dominance from D. gigas to T. sarmaticus indicates changing climatic and environmental conditions during the Oakhurst period, 14–7 ka. EMAIL: [email protected] Introduction DATES: Early evidence for the exploitation of shellfish for subsistence traces back to at least 164 ka during the Middle Stone Received: 11 Sep. 2018 Age (MSA) in South Africa1, and by 100–60 ka shellfish were systematically and intensively exploited at a handful of Revised: 03 Mar. 2019 sites2-5. Evidence for the use of shellfish for purposes other than food, such as making containers and ornaments, Accepted: 16 May 2019 appears from 100 ka to 75 ka in the southern Cape.6-8 It is, however, possible that many older sites containing shellfish Published: 26 Sep. 2019 remains were destroyed by the Marine Isotope Stage 5e sea level transgression.1 Further, there is little evidence for shellfish exploitation between 50 ka and 14 ka, mainly because of the paucity of coastal sites from this time period. HOW TO CITE: Ryano KP, Van Niekerk KL, Wurz Evidence for shell-fishing re-appears at around 14 ka in the southern Cape,9 at the end of the period associated S, Henshilwood CS. Shellfish with the Robberg techno-complex. Shellfish become more abundant in sites during the subsequent period linked exploitation during the Oakhurst at Klipdrift Cave, southern to the Oakhurst techno-complex, around 14–7 ka, although sites from this period with shellfish are still relatively Cape, South Africa. S Afr J Sci. uncommon.10,11 The most abundant evidence for intensive shellfish exploitation comes from the ‘megamidden’ 2019;115(9/10), Art. #5578, period, between 3 ka and 2 ka, from the West coast, which is dotted with extensive open shell middens.12 9 pages. https://doi.org/10.17159/ sajs.2019/5578 Here we present new data on shellfish exploitation during the Oakhurst period from a recently excavated Later Stone Age (LSA) site – Klipdrift Cave (KDC) – situated in the southern Cape. We compare our data to those from ARTICLE INCLUDES: contemporary sites in the region by examining the role that shellfish played in the subsistence of these coastal Peer review ☒ dwellers. Climatic and predation pressure hypotheses are examined against these data. We investigate three main Supplementary material ☒ issues: the nature of marine shellfish exploitation; the intensity of shellfish collection; and the extent to which climate and environmental conditions can be deduced from shellfish remains. DATA AVAILABILITY: Open data set ☐ The Oakhurst period in context All data included ☒ 10,13 On request from author(s) The term Oakhurst techno-complex is used here for sites that typically date to ~14–7 ka and that follow the ☐ Not available Robberg techno-complex, although regional variants occur across southern Africa14. Furthermore, the transition ☐ Not applicable 11 ☐ between entities such as the Robberg and Oakhurst in the Cape region was not synchronous. The Oakhurst is characterised by non-microlithic and bladelet poor lithic assemblages dominated by unstandardised flakes, and EDITOR: frequent use of coarser grained lithic raw materials.15-17 Formal tools are rare and consist mainly of medium to Maryna Steyn large scrapers. Non-lithic artefacts associated with the Oakhurst include worked bone, ostrich eggshell beads and ornaments as well as worked marine shell and beads.10 The Robberg period is characterised by relatively KEYWORDS: few shellfish remains, but during the Oakhurst, shellfish, fish, marine mammals and seabirds are present in the shell-fishing, predation pressure, palaeoclimate, environment, Terminal deposits. Initially the Oakhurst people also hunted large-to-medium-sized game such as eland and warthog, but 18 Pleistocene, coastal subsistence these prey were later replaced by browsers, likely reflecting a change towards a woodier habitat. FUNDING: Shellfish remains during the Oakhurst Complex on the southern Cape coast Research Council of Norway, Of the eight securely dated Oakhurst sites (Figure 1a) in the southern Cape10, four – Nelson Bay Cave (NBC)9, Matjes University of Bergen, University River Shelter (MRS)19, Byneskranskop 1 (BNK 1)20, and Oakhurst Shelter21 – contain significant shellfish remains, of the Witwatersrand, National 15 Research Foundation (South Africa), probably because they were close to the coast. At inland sites such as Boomplaas Cave (BPA) and Kangkara Cave, Palaeontological Scientific Trust Wilton Large Rock Shelter22 and Melkhoutboom Cave23, shellfish are rare, and, when present, may have predominantly (PAST), European Research Council been used for non-subsistence purposes such as the manufacture of ornamental and decorative items. The shellfish from three of the four sites have been described to varying degrees. The shellfish from Oakhurst Shelter were listed to species level but not quantified. The impression is that the shellfish samples were not retained during © 2019. The Author(s). Published excavation.24 It is, however, evident that the white sand mussel (Donax serra) is the most common species in the under a Creative Commons Oakhurst levels.21 Therefore, NBC, MRS and BNK 1 are described in more detail below. Attribution Licence. Research Article Volume 115| Number 9/10 https://doi.org/10.17159/sajs.2019/5578 1 September/October 2019 Oakhurst at Klipdrift Cave and shellfish exploitation Page 2 of 9 18°0'0"E 19°0'0"E 20°0'0"E 21°0'0"E 22°0'0"E 23°0'0"E 24°0'0"E 25°0'0"E a 33°0'0"E 34°0'0"E 35°0'0"E M.A.S.L b 35 30 25 20 15 10 5 SURFACE JY cal BP 10760-11170 JYA JZ JZA cal BP 12735-13000 JZB KAB cal BP 13405-13560 KAC KAD cal BP 13375-13555 cal BP 13480-13740 c KAE Figure 1: (a) Sites containing material from the Oakhurst Complex in the southwestern Cape, (b) Klipdrift Complex (Klipdrift Cave is the western section and Klipdrift Shelter is to the east), and (c) part of the Klipdrift Cave natural stratigraphic profile and associated accelerator mass spectrometry dates (dates provided by Beta Analytics). NBC and MRS are situated approximately 10 km apart with similar shellfish table, they were not convinced that they were brought in rocky shores and sandy beaches in close vicinity. The most common primarily as food, but suggest that they had been used as artefacts, as species in the Oakhurst levels are the bivalves Perna perna (brown some perforated fragments were found.20 Modified D. serra shells have mussel), D. serra and Choromytilus meridionalis (black mussel). At both not been reported from NBC and MRS. sites, there is an inverse correlation in the frequency of these species over time.9,19 At NBC, C. meridionalis is replaced by P. perna around Shellfish as a proxy for human population sizes 9,11 10 ka whilst D. serra frequencies increase at the same time. At MRS, It has been argued that the sizes of gastropods, and variation in shellfish 13 P. perna increases sharply relative to C. meridionalis by 9.5 ka , but, species, from archaeological sites may provide an estimate of the extent unlike at NBC, D. serra is most common in the earlier layers, dated to and intensity of harvesting of these animals as food, which in turn can be 19 10 ka, and decreases as P. perna increases . These changes in species used as a reflection of human population size.4,25,26 The reduced size of representation over time have been interpreted as indicative of changing gastropods in LSA sites relative to those from MSA localities in southern 9,19 environmental conditions. Africa has been used to imply intensified collection due to higher